[Solved] segfault with simple GGraphicsView

brandont

'ello everyone.
I'm just doing a few tests with QGraphicsView, and came across this strange segfult. This program was just suppose to display red dot (which I intended on animating).

main.cc
@
#include <QApplication>
#include "QtDots.h"

int main(int argc, char *argv[]) {
QApplication q_application(argc, argv);

QtDots dots;
dots.show();

return q_application.exec&#40;&#41;;

}
@

QtDots.h
@
#ifndef QTDOTS_H
#define QTDOTS_H

#include <QObject>
#include <QWidget>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsEllipseItem>

class QtDots : public QGraphicsView {
Q_OBJECT
private:
QGraphicsScene scene;
QGraphicsEllipseItem dot_1;
int y;
public:
explicit QtDots(QWidget *parent = 0);
};

#endif // QTDOTS_H
@

QtDots.cc
@
#include <Qt>
#include <QWidget>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QBrush>
#include <QGraphicsEllipseItem>
#include <QPainter>
#include "QtDots.h"

QtDots::QtDots(QWidget *parent)
: QGraphicsView(parent), dot_1(0, &scene) {
scene.setBackgroundBrush(QBrush(Qt::black));
scene.setSceneRect(0, 0, 400, 400);

y = 0;
dot_1.setBrush(QBrush(Qt::red));
dot_1.setPen(QPen(Qt::red));
dot_1.setRect(175, 0, 50, 50);

setScene(&scene);
resize(410, 410);
setRenderHints(QPainter::Antialiasing);

}
@

The segfault occurs at 'setScene(&scene)'. Whats strange is if you comment out 'y = 0', the segfault disapears. Can someone explain to me where my problem is?
Thanks!

vlad2048

Hi

Try this:
@
privite:
QGraphicsScene *scene;
QGraphicsEllipseItem *dot_1;
//...
QtDots::QtDots(QWidget *parent)
: QGraphicsView(parent)
{
scene = new QGraphicsScene;
//...
dot_1 = scene->addEllipse(150, -25, 50, 50);
dot_1->setBrush(...
//...
}
@

brandont

Thanks alot!